Infants normally begin to sit between the age of three and nine months, and also to use high chairs for eating at this time. Such chairs typically may have a flat seat, a back, and two arm rests or sides. A tray may also be provided, spaced above the seat and forwardly of the back, and the infant's legs fit under the tray.
Because the infant may not be strong enough to sit erect, or may just be squirmy, it is not uncommon for the infant to slide forwardly on the seat, to a slouched position...even to the point of becoming trapped under the tray and/or sliding off the front of the chair. To prevent such, straps may be extended from the chair sides or chair back, and secured around the waist area of the infant.
When sitting erect, the infant may lean forward at the waist to position the head and mouth over the tray. For a very young infant, pillows may be wedged between the infant and the back and/or sides of the chair, to hold the body against the rear of the tray. As so positioned, the mouth is vertically aligned over the tray and it is but a short trip for the food, from a food container on the tray to the mouth. This provides that most food spilled from the eating utensil ends up on the tray for easy cleanup.
On the other hand, the slouched infant orients his/her mouth laterally offset from the tray, so that food dropping off of the eating utensil ends up on the person's lap and not the tray.
The aged or ill, in their weakened condition, also may readily slide on the chair seat to a slouched position, under the eating table or the like, with the same drawbacks as mentioned above concerning an infant.